For the first time since arriving in 2009, a dissatisfied Cristiano Ronaldo no longer sees his long-term future at Real Madrid and has made it known to Manchester United that he favours an eventual return to Old Trafford.

The development, which has been revealed to ESPN by well-placed figures close to both clubs as well as the player, tallies with Ronaldo's recent public comments regarding his next move.

In the last week, although initially unwilling to discuss his future, the forward has admitted that "anything is possible" and that, after his current contract runs out in 2015, "I don't know what will happen in the future".

Tellingly, those comments themselves mirror Ronaldo's statements when he was trying to engineer a move to Real Madrid back in 2008 and 2009. Although that eventual world-record transfer was the fulfilment of a lifelong dream for the Portuguese, he has become concerned about the Spanish champions' capability of regularly matching his current ambitions.

Ronaldo is said to be dismayed at the state the team are currently in as well as the rapid regression following last season's record-breaking title win. Exacerbating that are issues including a perceived failure to back the player in his Ballon d'Or campaign, the state of siege in which his manager Jose Mourinho now finds himself, and the apparent infighting as a result of the unrest.

With the Real boss almost certain to depart the club in the summer, Ronaldo is concerned about where the club go next.

The situation is a far cry from the stability and regular trophies he experienced during his last three years at Old Trafford under Sir Alex Ferguson - with whom he has maintained contact.

Those at United were surprised but encouraged by the developments, although they understand that the situation is far from straightforward and any transfer would only come in the long term.

For a start, a major trophy like the Champions League - coincidentally, Madrid face United in the last-16 of the competition - could help to ease the situation at the Bernabeu. That was what happened with Mourinho's own uncertain situation last season after the league title win.

If that does not happen, Ronaldo's emotional connection to Old Trafford and his strong willingness to work with Ferguson again must be balanced against his long-held ambition to become the best-paid and most prestigious player in the world.

Although the Glazers have been occasionally willing to deviate from transfer policy to keep United competitive at the top level - as with the Robin van Persie signing - they still generally operate within the financial constraints they have themselves imposed.

An example came following the capture of Van Persie. Although Ferguson was still insistent on capturing Leighton Baines, Everton's greatly increased asking price of £18 million for the left-back meant the Glazers were unwilling to sanction another high fee so soon after Van Persie.

Meeting Ronaldo's market value - of which the player is understandably aware, despite any emotion about his old club - would involve a few big decisions. The club's hierarchy, however, would also look at his commercial potential, which has grown dramatically since he left in 2009.

However, if Ronaldo chooses to leave Real at the end of his current deal in the summer of 2014 that would negate the need for any transfer fee and create much greater flexibility on the value of his playing contract.

Ronaldo may still look to Paris Saint-Germain. The forward is understood to be too loyal to his past to consider a move to either Manchester City or Chelsea, leaving the French side as one of the few elite clubs that could afford him in the event he leaves Madrid.

One Old Trafford source said that "the situation can change but it's one to keep an eye on".

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